I recommend this tutorial for all new folks:http://learn.wordpress.com/get-flashy/
That is the page about inserting pictures, but the whole tutorial would be useful to get yourself acquainted with WordPress.com.

Do NOT copy / paste from Word!!
For one thing, in order to have pictures you must either upload them to your media library or link to them online (Flickr for example).
But the main reason not to paste from Word is that though it's a fine word processor, it does not speak "internet" very well at all. It adds all sorts of junk code which could break your theme. If you must paste from Word, do this:http://en.support.wordpress.com/microsoft-word/
or this:http://en.support.wordpress.com/word-web-app/